Investigations are being conducted into the biochemical composition of the sensory retina, pigmented epithelium and choroid in normal and disease states, particularly in animal models of human retinal deterioration and diseased human ocular tissues. The tissue specific distributions of inorganic constituents is studied by flameless atomic absorption, with concentrations of Ca, Cu and Zn of particular interest. The effects of nutrition and genetic background on the progress of chorioretinal deterioration and cataract formation in the retinal dystrophic pigmented RCS rat are under study. Diabetic rodents are being followed for the development of retinal disease that may model human diabetic retinopathy.